Problem accessing google drive with google apps script - google-apps-script

Question

So I wrote a bot with GAS for Slack and everything works fine. Now I made a copy of the bot and it starts giving out weird error "We're sorry, a server error occurred. Please wait a bit and try again." when I try to access a folder in Google drive. Since the code is exactly the same, I have no idea what the problem is.
//Create Pdf
function exportCurrentSheetAsPDF_() {
var ss = SpreadsheetApp.openById(MAIN_SPREADSHEET_ID);
var currentSheet = ss.getSheetByName(ASAKAWA_HOLIDAY_SHEET);
var blob = getAsBlob(ss.getUrl(), currentSheet);
var date = Utilities.formatDate(new Date(), 'Asia/Tokyo', 'YYYYMMddhhmmss');
var pdfName = mergePdfName("休日", date, "浅川Only", "H");
//Export pdf to google drive 008.2 Entertainment folder
exportPdfToDrive(blob, pdfName);
return pdfName;
}
function exportPdfToDrive(blob, fileName) {
blob = blob.setName(fileName);
var folder = DriveApp.getFolderById(GOOGLE_DRIVE_FOLDER_ID); <--- This gives error
var pdfFile = folder.createFile(blob);
}
//Get spreadsheet as blob
function getAsBlob(url, sheet, range) {
var exportUrl = url.replace(/\/edit.*$/, '')
+ "/export?exportFormat=pdf"
+ "&format=pdf"
+ "&size=A4"
+ "&portrait=true"
+ "&fitw=true"
+ "&sheetnames=false"
+ "&printtitle=false"
+ "&pagenum=false"
+ "&gridlines=false"
+ "&fzr=FALSE"
+ "&gid=" + sheet.getSheetId();
var response = UrlFetchApp.fetch(exportUrl, {
headers: {
Authorization: 'Bearer ' + ScriptApp.getOAuthToken(),
},
})
return response.getBlob();
}